Determine the zeros of the quadratic function y = x^2 + 15x + 26. (When listing the smaller zero, remember that negative values are always smaller than positive values.)

1 answer

To determine the zeros of the quadratic function \( y = x^2 + 15x + 26 \), we can use the quadratic formula:

\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]

where \( a = 1 \), \( b = 15 \), and \( c = 26 \).

First, we need to calculate the discriminant \( b^2 - 4ac \):

\[ b^2 = 15^2 = 225 \]

\[ 4ac = 4 \times 1 \times 26 = 104 \]

Now, compute the discriminant:

\[ b^2 - 4ac = 225 - 104 = 121 \]

Since the discriminant is positive, we will have two distinct real zeros.

Now, substitute back into the quadratic formula:

\[ x = \frac{-15 \pm \sqrt{121}}{2 \cdot 1} \]

Simplifying this further:

\[ \sqrt{121} = 11 \]

Now we have:

\[ x = \frac{-15 \pm 11}{2} \]

Calculating the two values:

  1. For \( x = \frac{-15 + 11}{2} \):

\[ x = \frac{-4}{2} = -2 \]

  1. For \( x = \frac{-15 - 11}{2} \):

\[ x = \frac{-26}{2} = -13 \]

Thus, the two zeros of the quadratic function \( y = x^2 + 15x + 26 \) are:

\[ x = -13 \quad \text{and} \quad x = -2 \]

In summary, the smaller zero is \( -13 \) and the larger zero is \( -2 \).

Therefore, the final answer is:

\[ \text{Zeros: } -13, -2 \]